Children play as Chinese paramilitary policemen (R) keep watch on Tiananmen Square in Beijing on June 3, 2009. Chinese police tightened restrictions on perceived trouble makers on the eve of the 20th anniversary of the crackdown on Tiananmen democracy protests, where hundreds, if not thousands of unarmed protesters and ordinary citizens were killed in the streets of Beijing as the military moved in to quell seven weeks of peaceful democracy protests. AFP PHOTO / Peter PARKS (Photo credit should read PETER PARKS/AFP/Getty Images)